Relationship Attributes in ER Diagrams
Can a relationship in an entity relationship diagram have its own key? If not, do we need to make a separate object with this key?
+3
user1121504
source
to share
1 answer
The only kind of relationship that has its own key would be a many-to-many relationship. The key of this relationship is, naturally, the combination of foreign keys with each of its parents.
If there are other attributes of a relationship, then it is not a relationship at all, it is an entity in itself.
Keys associated with one-to-many (and one-to-one) relationships are found in the child table as foreign keys.
+4
Joel brown
source
to share